Adding a footswitchable solo boost to a Mesa Rectifier 2 channel?

[mike80]

I'm fairly sure it wouldn't be hard, just how do I go about it? I think it would be just a matter of adding another Master Volume pot, but I'm not sure of the footswitching deal. Maybe a relay?

Any thoughts?

[recto-robbie]

I highly suggest checking this forum out. It will be in there if it can be done.

http://forum.grailtone.com/

[mike80]

I posted there too.

There seems to be more knowledgeable amp builders here, so I figured I would try here as well.

[RedMan]

You could just lift the ground off the mid control or disconnect the negative feedback. Those are relatively non invasive mods.

[mike80]

You could just lift the ground off the mid control or disconnect the negative feedback. Those are relatively non invasive mods.

Please pardon my ignorance on the subject, and I'm not trying to be sarcastic, but how would that accomplish a volume boost?

[VanR]

Please pardon my ignorance on the subject, and I'm not trying to be sarcastic, but how would that accomplish a volume boost?

Lifting the ground of the mid pot takes the tone stack out of the circuit. Well in most Marshall-type amps anyway. Thus allowing more signal to get to the power amp. So you get a marked increase in volume. I have done this to my 2 High Octane homebrews and even made it footswitchable. Gives a nice boost in volume for leads, but your tone will change due to the tone stack not being there. I used switching jacks to make it footswitchable.

[RedMan]

It doesn't take the tone stack out of the circuit but it lets the mids come thru that are otherwise shunted to ground. Not a bad way to go for a lead sound. The negative feedback circuit disconnect gives you more gain and a more organic less hifi sound, also great for leads.

[mike80]

I see. I'll have to give that a shot. I'm not wanting to alter the amp too much, just in case I decide to sell it in the future, so both of those mods sound like they might be the ticket.

Thanks much.